Velge P, Bottreau E, Kaeffer B, Pardon P
Centre de Recherche, Institut National de la Recherche Agronomique de Tours-Nouzilly, France.
Med Microbiol Immunol. 1994 Jul;183(3):145-58. doi: 10.1007/BF00196049.
Recent outbreaks of human listeriosis have emphasized the importance of food in the etiology of epidemic listeriosis, suggesting that the gastrointestinal tract is the natural site of entry for Listeria monocytogenes into the organism. L. monocytogenes invasion of finite cell lines derived from the porcine ileum exhibited a 100-fold lower penetration level, without any intracellular multiplication, when compared to CaCo-2 cells, a widely used in vitro model for L. monocytogenes invasion. Same results were obtained with both pig kidney primary cells and mouse kidney finite cell lines. To demonstrate that cell immortalization enhances L. monocytogenes invasion, finite cell lines from porcine ileum and from murine kidney were immortalized by Simian virus 40 (SV40) large T oncogene. Unlike their untransformed counterparts, the immortal cells obtained were invaded by L. monocytogenes, as observed for CaCo-2 cells as well as for spontaneously immortal human (HeLa) and murine (3T3) cell lines. Extensive electron microscopy examinations of porcine epithelioid cells infected by L. monocytogenes showed numerous bacteria within the immortal cells, whereas neither intracellular bacteria nor any bacterial antigen were revealed inside finite cell lines. These data suggested that L. monocytogenes were not destroyed inside finite cell lines but only poorly entered the finite or primary cells. Speculating that L. monocytogenes invasion is under control of differentiation or proliferation of the cells, only an enterocyte subset at a defined state of differentiation or expressing particular receptors could be invaded in vivo.
近期人类李斯特菌病的暴发凸显了食物在流行性李斯特菌病病因学中的重要性，这表明胃肠道是单核细胞增生李斯特菌进入机体的天然部位。与广泛用于单核细胞增生李斯特菌侵袭研究的体外模型CaCo-2细胞相比，单核细胞增生李斯特菌对源自猪回肠的有限细胞系的侵袭穿透水平低100倍，且无细胞内增殖现象。猪肾原代细胞和小鼠肾有限细胞系也得到了相同结果。为证明细胞永生化增强了单核细胞增生李斯特菌的侵袭能力，用猴病毒40（SV40）大T癌基因使源自猪回肠和小鼠肾的有限细胞系永生化。与未转化的对应细胞不同，所获得的永生化细胞被单核细胞增生李斯特菌侵袭，这与CaCo-2细胞以及自发永生化的人源（HeLa）和鼠源（3T3）细胞系的情况相同。对受单核细胞增生李斯特菌感染的猪上皮样细胞进行的广泛电子显微镜检查显示，永生化细胞内有大量细菌，而有限细胞系内未发现细胞内细菌或任何细菌抗原。这些数据表明，单核细胞增生李斯特菌在有限细胞系内未被破坏，只是很难进入有限细胞系或原代细胞。推测单核细胞增生李斯特菌的侵袭受细胞分化或增殖的控制，只有处于特定分化状态或表达特定受体的肠上皮细胞亚群在体内才会被侵袭。
